 public class Example4_7 {

   public static void main(String args[]) {

      Battery nanfu = new Battery(100);

      System.out.println("南孚电池的储电量是:"+nanfu.electricityAmount);

      Radio radio = new Radio();

      System.out.println("收音机开始使用南孚电池");

      radio.openRadio(nanfu);

      System.out.println("目前南孚电池的储电量是:"+nanfu.electricityAmount);

   }

}
